* Bump Substrate to version used by Polkadot (`5f056830`)

* Use `log` crate for runtime logging

See https://github.com/paritytech/substrate/pull/8128/ for more info.

* Stop using return value from `execute_block`

* Update test weight

* Add relevant storage items from Substrate pallet

* Add function for importing finalized headers to storage

* Remove unused getter functions

* Add GenesisConfig to pallet

* Add initialization extrinsic

* Add operational extrinsic

* Get existing finality verifier tests compiling again

* Add tests for pallet initialization

* Add tests related to pallet's operational status

* Update tests which were using `pallet-substrate-bridge`

* Add tests related to header imports

* Use wrapper function when init-ing some tests

* Add prefix to tests related to rate limiter

* Fix failed compilation related to GenesisConfig

* Add some documentation

* Change some extrinsics to be Operational

* Add public interface to pallet

* Implement runtime APIs for finality-verifier pallet

* Justify use of `expect` when importing headers

* Reject headers with forced changes

* Add weight to initialize extrinsic

* Remove TODO which will be addressed later

* Move succesful import log to correct location

* Expand proof for when `best_finalized` is fetched

* Move check for newer finalized blocks earlier in pipeline

* Rename `ConflictingFork` error to be more generic

* Only compute finality_target's hash once

* Add missing documentation to Runtime APIs

* Add TODO about using `set_id` from `ScheduledChange` digest

* Disable cache.

* Fix tests.

* Fix clippy?

* cargo fmt --all

* Use no-op ancestry checker

* Check that current header height is greater than last finalized

* Ensure that incoming headers are strictly greater than last finalized

* Ensure that header numbers always increase in tests

* Revert "Pin Rust Nightly to 2020-12-17 (#652)"

This reverts commit e54e6f7e.

* fix clippy

* clippy again

* more clippy in test code

* and new cargo fmt

* another try

* Bump substrate deps.

* Bump scale.

* Bump ethabi.

* Remove inherent from aura.

* Migrate to construct_runtime

* cargo fmt --all

* Add simple rate limiting mechanism

* Add tests

* Small test cleanup

* Hook MaxRequests into runtimes

* Make AncestryProof type more flexible

* Only import single finalized header instead of a chain

* Fix unchecked header import tests

* Add option for limiting ancestry proof size

* Update finality verifier Config in runtimes

* Update some documentation

* Fix Clippy warning

* Allow AncestryChecker to return proof size

Stops us from abusing the `Size` trait

* Remove Size impl for Vec<T>

* Remove size contraints for ancestry proofs

With different proof types its unclear how to "size" should be interpreted,
so we remove this requirement all together to avoid confusion.

* Add some logging to the finality verifier pallet

* Add finality target to happy path log

* Add Finality Verifier pallet to runtimes

* Implement simple ancestry checker

* Use the new checker in runtimes

* Remove unused import warning

* Bump max allowed ancestry proof size

* Add a few optimization suggestions when verifying ancestry

* Use session length as upper bound for ancestry proof size

* Remove unused time units

* Add test for invalid set id.

* cargo fmt --all

* Update modules/finality-verifier/src/lib.rs

Co-authored-by: Hernando Castano <[email protected]>

Co-authored-by: Hernando Castano <[email protected]>

* Add method for unchecked header imports

* Update docs for importing unchecked headers

* Import unchecked headers in HeaderChain implementation

* Fix Clippy warnings

* Move unchecked header import out of Verifier struct

* Clean up unchecked import tests

* Change HeaderChain API to accept iterator of headers

* Use chains of headers in tests

* Remove unused Result return type when appending finalized headers

* Add test which shows that genesis changes are not enacted

* Use initial header's hash for unchecked authority set changes

* Appease Clippy

* Check ancestry before making unchecked writes

* Fix typo

* Fix Clippy warning

* Add note about `ancestry_proof` structure

* Use best hash storage item directly

Co-authored-by: Svyatoslav Nikolsky <[email protected]>

* Get pallet compiling with FRAME v2

* Get tests compiling

* Stop printing metadata in tests

* Remove more metadata related code

* Remove unecessary storage attribute

* Add skeleton for `pallet-finality-verifier`

* Sketch out implementation for importing finality proofs

* Get pallet compiling

* Introduce skeleton for mock runtime

* Start using real Grandpa types in finality pallet

* Redefine types in header chain primitives crate

* Implement HeaderChain for Substrate bridge pallet

* Plug Substrate Bridge Pallet into verifier mock

* Fix compilation of `header-chain` primitives

* Start writing to base pallet storage

* Add first "cross-pallet" test

* Move keyring primitives used in tests to shared crate

* Stop pulling `std` deps into `no_std` builds

* Revert "Stop pulling `std` deps into `no_std` builds"

This reverts commit f74dd660.

* Revert "Move keyring primitives used in tests to shared crate"

This reverts commit b774fa73.

* Use new SS58Prefix type in mock

* Start using `bp-test-utils` in finality pallet

* Start using real justification code

* Get a test working with real justification verification

* Add basic tests for invalid proofs

* Get rid of AncestryProof config type

* Add error types to transaction outcome

* Bound number of headers allowed in a single ancestry proof

* Disallow invalid authority sets

* Remove unused items

* Add some documentation

* Get rid of Clippy warnings

* Rename BaseHeaderChain to TransactionVerifier

* Remove unused code

* Make dummy trait implementations more generic

* Fix more Clippy complaints

* Update tests to use fix for duplicate headers

* Fix benchmarking compilation

* Rename TransactionVerifier to InclusionProofVerifier